Method for melt pool monitoring using fractal dimensions
AssigneeGeneral Electric Company
InventorThomas Graham Spears
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Abstract
A method of controlling an additive manufacturing process in which a directed energy source is used to selectively melt material to form a workpiece, forming a melt pool in the process of melting, the method comprising: using an imaging apparatus to generate an image of the melt pool comprising an array of individual image elements, the image including a measurement of at least one physical property for each of the individual image elements; from the measurements, mapping a melt pool boundary of the melt pool; computing a fractal dimension of the melt pool; and controlling at least one aspect of the additive manufacturing process with reference to the fractal dimension.
Claims18
A method of controlling an additive manufacturing process in which a directed energy source is used to selectively melt material to form a workpiece, forming a melt pool in the process of melting, the method comprising:
- using an imaging apparatus to generate an image of the melt pool comprising an array of individual image elements, the image including a measurement of at least one physical property for each of the individual image elements;
- from the measurements, mapping a melt pool boundary of the melt pool;
- computing a fractal dimension of the melt pool and evaluating the fractal dimension for indications of a process fault, wherein the fractal dimension exceeding a predetermined limit value indicates a process fault;
- and
- controlling at least one aspect of the additive manufacturing process with reference to the fractal dimension by changing at least one process parameter of the additive manufacturing process in real-time during the forming of the workpiece.
A method of making a workpiece, comprising:
- depositing a material in a build chamber;
- directing a build beam from a directed energy source to selectively fuse the material in a pattern corresponding to a cross-sectional layer of the workpiece, wherein a melt pool is formed by the directed energy source;
- using an imaging apparatus to generate an image of the melt pool comprising an array of individual image elements, the image including a measurement of at least one physical property for each of the individual image elements;
- from the measurements, mapping a melt pool boundary of the melt pool;
- computing a fractal dimension of the melt pool and evaluating the fractal dimension for indications of a process fault, wherein the fractal dimension exceeding a predetermined limit value indicates a process fault;
- and
- controlling at least one aspect of making the workpiece with reference to the fractal dimension by changing at least one process parameter of a process of making the workpiece in real-time during the making of the workpiece.
Dependencies are inferred from the claim text.